Hot water heating system control



June 19, 1956 E. coLLAT 2,751,155

HOT IATER HEATING SYSTEM CONTROL Filed May 20, 1955 2 Shoeta-Sh'o'ot 1 /4 ms 6 ii 25 COOLlNG UNIT MJW gfdqir LW/if June 19, 1956 E. COLLAT 2,751,155

HOT WATER HEATING SYSTEM CONTROL Filed May 20, 1955 2 Sheets-Sheet 2 I2I IIT TEST NO. I

ROOM THERMOSTAT SATISFIED ROOM THERMOSTAT TEST NO. 2 SATISFIED BEFORE TIME CYCLE FINISHED RADIATOR TEMPERATURE 6 TIME MIN. 0 Z 4 6 8 I0 I2 I4 I6 I8 20222426363032543638 4O I25 I20 H5 IIO 0 I0 20 3O 4O 50,

TIME MIN. 3

TEST N0. 2 TEST NO.I

BOILER WATER TEMPERATURE 2,751,155 nor WATER HEATING SYSTEM oNTRoL Edgar Collat, Milwaukee, Wis., assignor o Ira Milton Jones, Milwaukee, Wis.

Application May 20, less, Serial No. 509,820 5 Claims. (Cl. 236-46) one-half to a 2 rise in temperature from 70 to 72 required forty minutes of pump operation. During the first six minutes, the temperature at the radiators rose from 65 F. to 133 water heating systems.

With the above and other objects in view, which will appear as the description proceeds, this invention resides in the novel method and construction, combination and nited States Patent Patented June 19, 1956 2 embodiment of the hereindisclosed invention may be made as come within the scope of the claims.

The accompanying drawings illustrate one complete ex- Figure 1 is a diagrammatic illustration of one embodiment of this invention;

Figure 2 is a graph comparing radiator temperatures taken during two tests of a hot water heating system, the first with the system operated in the conventional manance with this invention; and

Figure 3 is a graph comparing the boiler water temperatures of the system during these two tests. I Referring now particularly to the accompanying drawings, the numeral 5 designates generally a boiler or heatperature of the water in the boiler, and which may be set to maintain the desired water temperature as for instance F.

The water heated in the boiler is circulated through one or more radiators 6 located in the space or rooms to be heated, and connected with the boiler in a closed system, the circulation being etfected by a pump 7 driven by an electric motor 8.

If the system is intended for cooling as well as heating,

nected in series circuit with the thermostat, the solenoid 13 and a source of low voltage 16. It follows, therefore, that closure of the thermostat 14 will start the pump switch 15 is closed. I

The electric clock timing mechanism drives a cam shaft 21 upon which are mounted two switch controlling cams 22 and 23; the former controls the switch 15, and the switch, 24 is normally open, butits cam ldisso shaped marine; the fir st fewdegrees of its rot spondsto about two minutes, it close holds it closed duration ofthe complete time cycle is, of'course, subject to modification, but ithasbeen fou d that a cycle of twenty (20 minutes brings about the most eificient regulation of a hot water heating system.

The cam 22 which controls the swit h 15, is so shaped and placed upon the cam shaft" that: atthe start of the i e WhiQhFQ FF: th w tsh n for thebalance of the timefcycle. The

mi cygle, e w s 15 sfibssihnfl ma a ass?! for p x m t l ve i v min t s. hsii he. an. efiects opening of the switch to thereby stop the circulat ing pump motor. Preferably, the length of theactive surface 22' of the cam 22 is adjustable so that the portion of each cycle for which the pump operates may be varied within limits.

One end A of the active cam surface 22' maybe considered means for effecting the opening of the switch and its other end B may be considered means for effecting reclosure of the switch 15, and the location of this end B is such that reclosure of the switch 15 takes place just before the completion of the time cycle, Reclosure of the switch 15 restores control of the pump motorto the room thermostat 14, so that in the event the thermostat has not been satisfied during the complete period of the time cycle minutes) a second cycle of operation immediately follow.

To enable the system to be used for both heating and cooling, the thermostat 14 has two sets of stationary con tacts 14a and 14b, and the solenoids 13 and 20 are selectively connectable with either or these contacts by means of a switch 25. When the system is used for heat" ing, the stationary contact 14a is used since it is engaged in response to decreasing ambient temperature, and when the system is used for cooling the other stationary contact, 14b is connected in circuit. In either case therefore, it is closure of the thermostat which initiates the operation of the entire mechanism.

The advantages of this invention are graphically por trayed in the charts comprising Figures 2 and 3. InEigure 2 the curves designated ,TestNo. l" and Test No. 2 depict the radiator temperatures during two tests made with a hot water heating system, the first, with the system operating in the conventional manner and the second, with thisinvention incorporated in the system. It will be seen that in each instance the radiator temperature rose abruptly with the start of the circulating pum In Test No. 1, the pump continued to run fterthe radiator temperature reached maximum, and hencethe temperature dropped abruptly to 96 F. from which level it gradually climbed to 116 F., andwhen this temperature was reached the thermostat was satisfied and the pump stopped, but it took thirtyenine minutes to reach this point.

In Test No. 2, the opening of the time switch 15 stopped the pump at 6 minutes past the start of the cycle. Accordingly, the radiator temperature dropped gradually, and some time prior to completion of the twenty minute cycle, the room thermostat was satisfied. Thus, the desired increase in room temperature was attained at least 15 minutes faster during Test No. 2.

Comparison of the boiler water temperatures depicted by the curves designated Test No. 1 and Test No. 2, in Figure 3, are equally revealing. The significant observation is that in Test No. 2, the temperature of thewater in the boiler was restored to 185 F.,ftwenty-four minutes sooner than in TestNo. l.

It follows, therefore, that this invention possesses several very important advantages, notably:

'l. Faster and more effective space heating and more comfortable cooling.

2. Reduction in fuel consumptionbecause of quicker stantial improvement over comparable heat exchange systems heretofore available.

1 claim:

l. A heat exchange system, for controlling the temperature of a space, and wherein a liquid heat exchange medium is circulatedthrough heatjexchangers located in said space by an electric motor driven circulating pump in response to closure of a thermostat sensitive to the temperature of said space, characterized by the provision of: a timing mechanism; means to maintain the timing mechanismin operation for a definite time'cycle after being started; means responsive to closure of the the rmos tat and connected with the timing mechanism to start the same; a switchconnected in series with the thermostat and operatively connected with the control for the circulating pump motor so that both the thermostat and said switch must be closed for the circulating pump motor to run and whereby the opening of said switch stops the circulating pump motor despite the fact that the thermostat may not be satisfied','switch actuating means operated by the timing mechanism to open said switch after a predetermined time short of the complete time cycle of the timing mechanism; and other switch actuating means operated by' the timing mechanism at a later time in its cycle to reclose said switch and thereby restore the control of the circulating pump motor to the thermostat.

'2. A hot water heating system of the type wherein the thermostat to start the timing mechanism when the thermostat closes; switch means operated by the timing mechanism and connected with the circulating pump mo tor and the thermostat to take over control of the circulating pump motor and stop the samea'fter a predetermined time short of the time cycle of theitiming mechanism despite the fact that the'thermostat may still be closed; and means actuated by thetim ing mechanismbefore the completion of its time cycle and operable upon said switch means to eiiect reclosure of said switch means and thereby restore the control of the circulating pump motor to the thermostat.

3. A hot water heating system of the type wherein water heated in a boiler is circulated throughradiators located in the space to be heated, by an electric motor driven circulating pump in response to closure of a thermostat sensitive to the temperature of said space, characterized by the provision of: an electric clock timing mechanism; means to maintain the timing mechanism in operation for a definite time cycle after it has been started; switch means responsive to closure of the thermostat and connected'with the electric clock timing mechanism and a source of current to start the timing mechanism when the thermostat closes', a switch connected in series circuit with the thermostat and connected with the control for the circulating pump motor so that both the thermostat and said switch must be closed for the circulating pump motor to run; means driven'by the electric clock timing mechanism to open said switch after a predetermined time short'of the" complete time cycle of the timing mechanism and thereby stop the circ'u electric clock 4 lating pump motor despite the fact that the thermostat switch means and operable to open the same at a predemay not be satisfied; and other switch actuating means termined time interval after the start of the cam shaft operable upon said switch and driven by the timing cycle and to reclose the same Just before the completion mechanism to eifect reclosure of said switch prior to cornof the cam shaft cycle. pletion of the time cycle of the timing mechanism to 5 5. A control device for hot water heating systems in thereby restore the control of the circulating pump motor which the heated water is circulated through the system to the thermostat. by an electric motor driven pump, said control device 4. hot water heating system of the type wherein being adapted to control the operation of the water Cl!- water heated in a boiler is circulated through radiators culating pump and, comprising an electric clock mechalocated in the space to be heated, by an electric motor nism; means to start the clock mechanism upon closure driven pump, in response to closure of a thermostat sensiof a room thermostat controlling the operation of the tive to the temperature of the space to be heated, charheating system; switch means connected with the clock acterized by the provision of an electric clock mechamechanism to maintain the same 1n operation for a nism, means responsive to the closure of the thermostat definite time cycle after the clock mechanism has been and connected with the clock mechanism to start the same started; switch means operated by the clock mechanism when the thermostat closes; a cam shaft driven by the to take over control of the operation of the water clock mechanism to make one complete cycle in a precirculating pump from the thermostat so that the circudetermined period of time; switch means connected in lfiiiflg p mp m y be st pped efore the thermostat is parallel with the thermostat and connected with the clock Satisfied; and means operated by the clock mechanism mechanism to maintain the clock mechanism in operaj P e t0 the Completion of the time Cycle of the Clock tion despite opening of the thermostat; a cam on the cam mechanism to reset said last named switch means and shaft controlling said switch means, said cam holding the thus restore Control of the circulating P P t0 the switch means open at the start of the cam shaft circle thermostatand maintaining said switch means closed until ust before the cycle is completed so that said switch means main- References Cited in the file of this Pawnt tains the clock mechanism operative to complete the cam UNITED STATES PATENTS shaft cycle, regardless of the position of the thermostat;

other switch means connected in series with the thermostat and hence operable to control the circulating pump motor; and means on the cam shaft controlling said other 

